Should we buy our prom dresses two sizes too small or four sizes too small? That is the question. Judging from this teenybopper's excruciating battle to pull off a dress in the fitting room, I guess five sizes too small is the answer. A form-fitting gown is sexy, but if huffing, puffing, and a tub of butter is necessary to yank the dress off at the end of the night — ditch it. If you can.